Braking systems have been used for many years on vehicles such as trucks, trailers and the like. Similarly, break-away switches have been used for many years on trailers to help stop them if they become separated from the towing vehicle. Break-away braking systems have been used for years as shown in U.S. Pat. Nos. 3,907,071 and 4,052,695. These systems typically have an auxiliary battery mounted on the trailer which activates the electric brakes when the trailer breaks-away or becomes separated from the towing vehicle. U.S. Pat. No. 3,681,551 describes a disconnect safety switch used in a break-away braking system.
Known break-away switches suffer from a number of design deficiencies. Presently, break-away switches are mechanical devices that typically use a nonconductive mechanism to mechanically separate the contacts of the switch. When the nonconductive mechanism is removed, the contacts are typically actuated by springs to close the switch contacts. The use of contacts and springs produces undesirable failure modes. Although seals are added in an attempt to keep out contaminates, moisture condensation within the switch housing can cause corrosion of the contacts. The corroded contacts create a high resistance barrier between the contacts that is not removed with the simple closing motion of the contacts. Broken springs that fail to actuate the contacts or contaminates that become lodged between the contacts can also be a problem. All of these failure modes can result in a switch that is electrically ineffective even though its nonconductive mechanism has been removed.
Furthermore, when known break-away switches are submersed in conductive liquid or become contaminated with conductive material between the contacts, the trailer brakes can be inadvertently actuated. This can result in an application of the trailer brakes that can be hazardous.
It would be desirable therefore if there was a break-away switch that could overcome the problems discussed above and would provide the means to actuate the trailer brakes in the event of unintended decoupling of the trailer from the towing vehicle.